The present invention relates generally to catheter tubes and more specifically to anti-clotting methods and apparatus for catheter tubes.
Typically, for example only, many dialysis medical patients are treated for a few hours every two or three days. Dialysis is performed by removing blood from the patient through an effluent or egress catheter tube, processing the removed blood through an artificial kidney machine to filter impurities from the blood, and returning the cleansed or processed blood to the patient through an influent, infusion or ingress catheter tube. The two catheter tubes may be any of several configurations, including but not limited to two essentially separate catheter tubes, a dual lumen catheter or any other suitable egress/ingress arrangement.
It is desirable to limit the number of times a vessel of the patient is penetrated for placement therein of dialysis catheter tubes. Accordingly, once placed, it is desirable for the distal end of the egress and ingress catheter tubes to be left indwelling for an extended period of time to accommodate spaced, repeated dialysis. Accordingly, the indwelling egress and ingress catheter tubes are inactive typically for much longer intervals than they are active. In addition, catheter tubes for other purposes are sometimes left indwelling for long periods of time and are frequently idle with no flow therethrough. This includes, but is not limited to, the central venous catheter category.
During idle times, when flow is not occurring in a given indwelling catheter tube, blood tends to enter the distal opening of the indwelling catheter tube. This is true even when the lumen of the catheter tube is full of liquid, other than blood, such as saline or heparin. During these idle times, blood flow through the vessel around the outside of the catheter tube tends to evacuate liquid from the lumen at the distal tip of the idle indwelling catheter tube, which is replaced by blood. This blood in the distal tip of each catheter tube tends to remain stationary, risking the development of a clot.
When clotting occurs within the lumen at the distal end of a catheter tube, an expensive clot-busting medication, such as Urokinase, is introduced into the proximal end of the catheter tube. After a suitable waiting period, during which the clot is softened, the medication and softened clot are aspirated from the catheter tube through the proximal end thereof. Where sufficient softening does not occur, the expensive clot-busting medication process may be repeated. Sometimes the clot is discharged into the vessel from the lumen using a liquid under positive pressure, which creates undesired risks for the patient. If all else fails, the catheter tube with the clot therein is removed from the patient at the vessel puncture site and a new replacement catheter tube inserted into the vessel.
Given the foregoing, provision of reliable and inexpensive methods and apparatus for avoiding or greatly alleviating clotting in indwelling catheter tubes would solve a long standing medical problem.
In brief summary, the present invention overcomes or substantially alleviates clotting problems heretofore associated with certain types of catheter tubes. The present invention utilizes an enabled or activated closure and sealing device and related methods to substantially preclude entry and clotting of blood at the distal end of a lumen of an indwelling catheter tube during times when flow therein is not occurring. The closure and sealing device is disabled or deactivated to accommodate flow, without clotting, through the lumen of the catheter tube when flow therein is initiated or resumed. In a presently preferred form, the closure device may comprise an inflatable/deflatable balloon, which, when inflated, closes the lumen of the catheter tube at the distal end thereof. The invention can be configured to accommodate flushing or purging of the lumen of the indwelling catheter tube either before or after inflated deployment of the balloon closure. The balloon mechanism may be inserted into the patient as the catheter tube is inserted, with the balloon either inflated or deflated, or separately after the catheter tube is first inserted. The invention applies to trimmable and non-trimmable catheters. The balloon may be a separate component or integrated with the catheter tube. Slit valve mechanisms may be used to control flow through the lumen of the catheter tube, to prevent or alleviate leakage at the proximal end of the catheter tube, and to control fluid flow to and from the balloon.
In view of the foregoing, it is a primary object of the present invention to overcome or materially alleviate clotting problems heretofore associated with certain types of catheter tubes.
Another important object is the provision of anti-clotting methods and apparatus for indwelling catheter tubes.
A further paramount object is the utilization of a closure and sealing device and related methods which, when the device is activated, substantially precludes entry and clotting of blood at the distal end of a lumen of an indwelling catheter tube during times when flow therein is not occurring and/or when the catheter tube and balloon are collectively introduced into the vessel.
Another dominant object is the provision of a closure and sealing device and related methods, which device can be activated to preclude entry and clotting of blood within a lumen of a catheter tube during introduction and/or during times when flow therein is not occurring and can be deactivated to accommodate flow through the lumen of the catheter tube.
It is another valuable object of the present invention to provide an inflatable/deflatable balloon device for selective closure of a lumen of a catheter tube at the distal end thereof, when inflated.
An additional significant object is the provision of a trimmable or non-trimmable catheter tube in combination with a balloon closure device at the distal end of the catheter tube which accommodates use of a liquid under pressure to flush or purge the lumen of the indwelling catheter tube, either before or after inflated deployment of the balloon closure.
A further valued object is the provision of novel balloon closures in combination with the distal ends of catheter tubes wherein a slit valve mechanism is used to control flow through the lumen of an associated catheter tube, to prevent or alleviate leakage at the proximal end of the catheter tube, and/or to control fluid flow to and from the balloon.
These and other objects and features of the present invention will be apparent from the detailed description taken with reference to the accompanying drawings.